Carbon dioxide metering system, ship, and carbon dioxide metering method

Abstract

In this carbon dioxide metering system, a delivery mass acquisition unit obtains the mass of the liquefied carbon dioxide stored in a tank, on the basis of the detection results of a level meter for detecting a liquid level in the tank, a tank thermometer for detecting a temperature in the tank, and a tank pressure gauge for detecting a pressure in the tank. The delivery mass acquisition unit obtains the mass of the liquefied carbon dioxide liquefied by a liquefaction unit and fed into the tank by a first piping system, on the basis of the detection result of a first flow meter. The delivery mass acquisition unit acquires the mass of the liquefied carbon dioxide delivered from the tank, on the basis of the obtained mass of the liquefied carbon dioxide stored in the tank, and the mass of the liquefied carbon dioxide fed into the tank by the first piping system.

Description

Carbon dioxide metering system, ship, and carbon dioxide metering method

[0001] This application claims priority to Japanese Patent Application No. 2023-125675, filed on August 1, 2023, the contents of which are incorporated herein by reference.

[0002] Patent Document 1 discloses a ship (liquefied carbon dioxide transport ship) equipped with a tank (LCD container) for storing liquefied carbon dioxide (LCD) and a pump (cargo discharge pump, booster pump) for discharging the liquefied carbon dioxide from the container. After arriving at a destination, such a ship unloads the liquefied carbon dioxide by discharging the liquefied carbon dioxide from the tank using the pump.

[0003] JP 2010-266068 A

[0004] Meanwhile, in ships and the like, in order to reduce greenhouse gas emissions, carbon dioxide is sometimes captured from exhaust gas generated when burning fuel, for example. The gaseous carbon dioxide captured from exhaust gas in this way may be liquefied and stored in a tank to save storage space. The liquefied carbon dioxide stored in the tank is unloaded at a port or the like, and the amount of liquefied carbon dioxide unloaded may be managed by mass. Generally, the amount of liquefied gas unloaded from the tank is measured using a level gauge that measures the liquid level in the tank. However, in ships and the like as described above, carbon dioxide may be captured from exhaust gas even while the liquefied carbon dioxide in the tank is being unloaded, causing liquefied carbon dioxide to flow into the tank, making it difficult to measure the mass of the liquefied carbon dioxide discharged from the tank with high accuracy.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a carbon dioxide metering system, a ship, and a carbon dioxide metering method that can obtain the mass of unloaded liquefied carbon dioxide with greater accuracy.

[0006] In order to solve the above problems, the carbon dioxide metering system according to the present disclosure comprises a carbon dioxide capture unit, a liquefaction unit, a tank, a first piping system, a level gauge, a tank thermometer, a tank pressure gauge, a first flow meter, and a discharged mass acquisition unit. The carbon dioxide capture unit captures gaseous carbon dioxide from a carbon dioxide-containing gas. The liquefaction unit liquefies the gaseous carbon dioxide captured by the carbon dioxide capture unit. The tank is capable of storing liquefied carbon dioxide. The first piping system sends the liquefied carbon dioxide liquefied by the liquefaction unit into the tank. The level gauge detects the liquid level in the tank. The tank thermometer detects the temperature in the tank. The tank pressure gauge detects the pressure in the tank. The first flow meter detects the flow rate of liquefied carbon dioxide sent to the tank by the first piping system. The discharged mass acquisition unit acquires the mass of liquefied carbon dioxide dispensed from the tank. The discharged mass acquisition unit determines the mass of liquefied carbon dioxide stored in the tank based on the detection results of the level gauge, the tank thermometer, and the tank pressure gauge. The discharged mass acquisition unit determines the mass of liquefied carbon dioxide delivered to the tank by the first piping system based on the detection result of the first flow meter. The discharged mass acquisition unit acquires the mass of liquefied carbon dioxide dispensed from the tank based on the determined mass of liquefied carbon dioxide stored in the tank and the mass of liquefied carbon dioxide delivered to the tank by the first piping system.

[0007] A vessel according to the present disclosure includes a hull and a carbon dioxide metering system as described above.

[0008] A carbon dioxide metering method according to the present disclosure is a carbon dioxide metering method for the carbon dioxide metering system described above. The carbon dioxide metering method includes the steps of acquiring the liquid level in the tank, acquiring the temperature and pressure in the tank, acquiring the flow rate of liquefied carbon dioxide fed from the liquefaction unit to the tank, and acquiring the mass of liquefied carbon dioxide dispensed from the tank. In the step of acquiring the mass of liquefied carbon dioxide dispensed from the tank, the mass of liquefied carbon dioxide dispensed from the tank is acquired based on the temperature and pressure in the tank, the amount of change in the liquid level in the tank, and the flow rate of liquefied carbon dioxide fed from the liquefaction unit to the tank.

[0009] According to the carbon dioxide metering system, ship, and carbon dioxide metering method disclosed herein, the mass of unloaded liquefied carbon dioxide can be obtained with greater accuracy.

[0010] FIG. 1 is a side view of a ship according to an embodiment of the present disclosure. FIG. 2 is a diagram showing the configuration of a carbon dioxide metering system according to an embodiment of the present disclosure. FIG. 3 is a diagram showing the hardware configuration of a calculation device provided in a ship according to an embodiment of the present disclosure. FIG. 4 is a functional block diagram of a calculation device provided in a ship according to an embodiment of the present disclosure. FIG. 5 is a diagram showing the liquid level in a tank after dispensing in a carbon dioxide metering system according to an embodiment of the present disclosure. FIG. 6 is a flowchart showing the steps of a carbon dioxide metering method according to an embodiment of the present disclosure.

[0011] A carbon dioxide metering system, a ship, and a carbon dioxide metering method according to embodiments of the present disclosure will be described below with reference to Figures 1 to 6. (Overall configuration of ship) As shown in Figure 1, a ship 1 according to this embodiment includes at least a hull 2, a combustion device 8, and a carbon dioxide metering system 20 (see Figure 2).

[0012] (Hull Structure) The hull 2 ​​has a pair of side walls 3A, 3B that form its outer shell, a bottom wall 4, and an upper deck 5. The side walls 3A, 3B are made up of a pair of side wall shell plates that form the port and starboard sides, respectively. The bottom wall 4 is made up of a bottom wall shell plate that connects the side walls 3A, 3B. The upper deck 5 is a full-length deck that is exposed to the outside. The hull 2 ​​has a superstructure 6 with accommodation areas formed on the upper deck 5, for example, on the stern 2b side.

[0013] The hull 2 ​​illustrated in this embodiment has a cargo carrying section (hold) 7 closer to the bow 2a than the superstructure 6. Furthermore, this cargo carrying section 7 is provided with a plurality of cargo tanks 11. Note that although the example has been given in which a plurality of cargo tanks 11 are provided in the cargo carrying section 7, the present invention is not limited to this configuration, and for example, various types of cargo, such as containers, may be loaded in the cargo carrying section 7. Furthermore, although the example has been given in which the hull 2 ​​has a cargo carrying section 7, the present invention is not limited to a hull 2 ​​having a cargo carrying section 7.

[0014] The combustion device 8 is a device that generates thermal energy by burning fuel, and is provided inside the hull 2. Examples of the combustion device 8 include an internal combustion engine used as a main engine for propelling the ship 1, an internal combustion engine used in a power generation facility that supplies electricity to the ship, and a boiler that generates steam as a working fluid. The combustion device 8 is connected to a fuel tank 9 provided inside the hull 2 ​​via a fuel supply piping system 101. The combustion device 8 combusts fuel supplied from the fuel tank 9 via the fuel supply piping system 101.

[0015] (Configuration of Carbon Dioxide Metering System) Fig. 2 is a diagram showing the configuration of a carbon dioxide metering system according to an embodiment of the present disclosure. As shown in Fig. 2, the carbon dioxide metering system 20 includes a tank 21, a first piping system 103, a second piping system 104, a carbon dioxide capture unit 23, a discharge piping system 105, a liquefaction unit 25, and a computing device 50.

[0016] The tank 21 is capable of storing liquefied carbon dioxide. The tank 21 illustrated in this embodiment is provided on the upper deck 5. The location of the tank 21 is not limited to being on the upper deck 5, and may be located, for example, below the upper deck 5. Note that while this embodiment illustrates an example in which one tank 21 is provided, the number of tanks 21 is not limited to one and may be multiple. Furthermore, while this embodiment illustrates an example in which a so-called horizontally placed cylindrical tank is used as the tank 21, the shape of the tank 21 is not limited in any way and may be spherical, rectangular, or the like.

[0017] The first piping system 103 connects the liquefaction unit 25 and the tank 21. The first piping system 103 sends liquefied carbon dioxide liquefied in the liquefaction unit 25 to the tank 21. The first piping system 103 of this embodiment continuously captures gaseous carbon dioxide in the carbon dioxide capture unit 23 and sends the liquefied carbon dioxide liquefied in the liquefaction unit 25 to the tank 21, for example, during a voyage of several days to several weeks. Furthermore, the first piping system 103 of this embodiment continuously captures gaseous carbon dioxide in the carbon dioxide capture unit 23 and sends the liquefied carbon dioxide liquefied in the liquefaction unit 25 to the tank 21 even during a berthing period. The amount of carbon dioxide captured during this berthing period may be smaller than during a voyage (a voyage of several days to several weeks).

[0018] A pump (not shown) for pressure-feeding liquefied carbon dioxide to the tank 21 is provided midway through the first piping system 103. Note that the pump may be omitted if the liquefied carbon dioxide can be transferred from the liquefaction unit 25 to the tank 21 due to the positional relationship and pressure difference between the liquefaction unit 25 and the tank 21. The first piping system 103 exemplified in this embodiment penetrates the top of the tank 21 and extends to the bottom of the tank 21 where it opens, but is not limited to this configuration and may have any configuration as long as it is capable of feeding the liquefied carbon dioxide liquefied in the liquefaction unit 25 into the tank 21.

[0019] The second piping system 104 connects the tank 21 to a manifold (not shown) provided on the hull 2. An external piping system for discharging the liquefied carbon dioxide in the tank 21 outside the ship can be connected to the manifold. The second piping system 104 extends upward from the lower part of the tank 21, penetrates the top of the tank 21, and extends toward the manifold provided outside the tank 21. A discharge pump 108 is provided at the tip of the second piping system 104 located at the lower part of the tank 21. The discharge pump 108 is capable of pressure-feeding the liquefied carbon dioxide in the tank 21 outside the tank 21. The second piping system 104 discharges the liquefied carbon dioxide pressure-feed by the discharge pump 108 outside the ship via the manifold (not shown). The second piping system 104 of this embodiment discharges the liquefied carbon dioxide that has been collected and stored over a period of several days to several weeks, for example, outside the ship within a few hours during the ship's berthing period. For this reason, when the ship is at anchor and liquefied carbon dioxide is being discharged from tank 21, the flow rate of liquefied carbon dioxide in first piping system 103 is sufficiently smaller than the flow rate of liquefied carbon dioxide in second piping system 104. The flow rate of second piping system 104 when the ship is at anchor and liquefied carbon dioxide is being discharged from tank 21 can be, for example, about 10 to several hundred times the flow rate of first piping system 103.

[0020] (Configuration of Carbon Dioxide Capture Unit) The carbon dioxide capture unit 23 is provided in the hull 2, and captures gaseous carbon dioxide from the exhaust gas of the combustion device 8, which is a carbon dioxide-containing gas. In this embodiment, the carbon dioxide capture unit 23 is provided on the upper deck 5 of the hull 2, but the location of the carbon dioxide capture unit 23 is not limited to on the upper deck 5.

[0021] The carbon dioxide capture unit 23 captures carbon dioxide (gas) contained in the exhaust gas sent from the combustion device 8 (see FIG. 1 ) through the exhaust gas pipe 102. Examples of methods for capturing carbon dioxide include a chemical absorption method in which carbon dioxide is absorbed in an absorbing liquid. An example of an absorbing liquid used when absorbing carbon dioxide by a chemical absorption method is monoethanolamine (MEA). The carbon dioxide capture unit 23 separates the carbon dioxide absorbed in the absorbing liquid in a gaseous state from the absorbing liquid by, for example, heating the absorbing liquid that has absorbed the carbon dioxide. This separated gaseous carbon dioxide is sent to the liquefaction unit 25. Here, the exhaust gas after the carbon dioxide has been absorbed in the absorbing liquid is subjected to, for example, a cleaning process and then released into the atmosphere through an exhaust funnel (not shown) or the like provided on the ship 1.

[0022] (Configuration of Liquefaction Unit) The liquefaction unit 25 liquefies the gaseous carbon dioxide recovered by the carbon dioxide recovery unit 23. In this embodiment, the carbon dioxide recovery unit 23 and the liquefaction unit 25 are connected by the discharge piping system 105, and the liquefaction unit 25 liquefies the gaseous carbon dioxide sent from the carbon dioxide recovery unit 23 through the discharge piping system 105. More specifically, the liquefaction unit 25 compresses the gaseous carbon dioxide sent through the discharge piping system 105 and liquefies this compressed gaseous carbon dioxide by cooling it. The carbon dioxide liquefied in the liquefaction unit 25 (hereinafter referred to as liquefied carbon dioxide) is sent into the tank 21 through the first piping system 103.

[0023] (Configuration for Metering Liquefied Carbon Dioxide Discharged from Tank) The carbon dioxide metering system 20 further includes the following components for measuring the mass of liquefied carbon dioxide discharged from the tank 21.

[0024] A first flow meter 91 is provided in the first piping system 103. The first flow meter 91 detects the flow rate of liquefied carbon dioxide fed to the tank 21 by the first piping system 103. The first flow meter 91 exemplified in this embodiment is a volumetric flow meter that detects the volumetric flow rate of the liquefied carbon dioxide fed to the tank 21 by the first piping system 103.

[0025] Further, a second flow meter 92 is provided in the second piping system 104. The second flow meter 92 detects the flow rate of the liquefied carbon dioxide discharged from the tank 21 by the second piping system 104. The second flow meter 92 illustrated in this embodiment is a volumetric flow meter that detects the volumetric flow rate of the liquefied carbon dioxide discharged from the tank 21 by the second piping system 104.

[0026] Furthermore, the tank 21 is provided with a level gauge 81, a tank thermometer 82, and a tank pressure gauge 83. The level gauge 81 detects the liquid level in the tank 21. The tank thermometer 82 detects the temperature of the liquefied carbon dioxide in the tank 21. The tank pressure gauge 83 detects the pressure (gas phase pressure) in the tank 21.

[0027] Furthermore, the first piping system 103 is provided with a first pressure sensor 85 and a first temperature sensor 86. The first pressure sensor 85 detects the pressure of the liquefied carbon dioxide sent from the liquefaction unit 25 to the tank 21 via the first piping system 103. The first temperature sensor 86 detects the temperature of the liquefied carbon dioxide sent from the liquefaction unit 25 to the tank 21 via the first piping system 103.

[0028] A purity detector 87 is provided in the second piping system 104. The purity detector 87 detects the purity of the liquefied carbon dioxide dispensed from the tank 21 via the second piping system 104. Furthermore, the first piping system 103 of this embodiment is provided with a purity detector 89 that detects the purity of the liquefied carbon dioxide sent from the liquefaction section 25 to the tank 21 via the first piping system 103. The purity detector 89 may be provided as appropriate and may be omitted, for example.

[0029] A fuel meter 88 is provided in the fuel supply piping system 101. The fuel meter 88 detects the flow rate of fuel supplied from the fuel tank 9 to the combustion device 8 via the fuel supply piping system 101. The fuel meter 88 can detect the amount of fuel consumed by the combustion device 8. In addition, the fuel supply piping system 101 is further provided with a fuel thermometer 84 that detects the temperature of the fuel supplied from the fuel tank 9 to the combustion device 8 via the fuel supply piping system 101.

[0030] (Hardware Configuration Diagram) Fig. 3 is a diagram showing the hardware configuration of a computing device according to an embodiment of the present disclosure. As shown in Fig. 3, the computing device 50 is a computer including a CPU (Central Processing Unit) 51, a ROM (Read Only Memory) 52, a RAM (Random Access Memory) 53, a storage 54, and a signal transmission / reception module 55. The signal transmission / reception module 55 receives detection signals from a first flow meter 91, a second flow meter 92, a level meter 81, a tank thermometer 82, a tank pressure meter 83, a first pressure sensor 85, a first temperature sensor 86, purity detectors 87 and 89, a fuel meter 88, and a fuel temperature meter 84.

[0031] (Functional Block Diagram) Fig. 4 is a functional block diagram of a control device according to an embodiment of the present disclosure. As shown in Fig. 4, a CPU 51 of a calculation device 50 executes a program stored in advance in a storage device such as a ROM 52 or a storage 54, thereby realizing the components of a signal input unit 70, an information acquisition unit 71, a delivery mass acquisition unit 72, and an information output unit 73.

[0032] The signal input unit 70 receives detection signals from each of the first flow meter 91, second flow meter 92, level meter 81, tank thermometer 82, tank pressure meter 83, first pressure sensor 85, first temperature sensor 86, purity detection meters 87, 89, fuel meter 88, and fuel temperature meter 84 via the signal transmission / reception module 55.

[0033] Based on the detection signals received by the signal input unit 70, the information acquisition unit 71 acquires the detection values ​​of each parameter detected by each of the first flow meter 91, second flow meter 92, level meter 81, tank thermometer 82, tank pressure meter 83, first pressure sensor 85, first temperature sensor 86, purity detectors 87, 89, fuel meter 88, and fuel thermometer 84.

[0034] The dispensed mass acquisition unit 72 acquires the mass of liquefied carbon dioxide dispensed from the tank 21 based on the detected values ​​of each parameter detected by each of the first flow meter 91, second flow meter 92, level meter 81, tank thermometer 82, tank pressure meter 83, first pressure sensor 85, first temperature sensor 86, purity detectors 87, 89, fuel meter 88, and fuel thermometer 84, which are acquired by the information acquisition unit 71.

[0035] 5 is a diagram showing the liquid level of the tank after dispensing in the carbon dioxide metering system according to an embodiment of the present disclosure. The dispensed mass acquisition unit 72 calculates the mass of liquefied carbon dioxide stored in the tank 21 based on the detection results of the level gauge 81, the tank thermometer 82, and the tank pressure gauge 83. As shown in FIG. 2, the dispensed mass acquisition unit 72 acquires the detected value of the liquid level L1 by the level gauge 81 before dispensing the liquefied carbon dioxide from the tank 21. Also, as shown in FIG. 5, the dispensed mass acquisition unit 72 acquires the detected value of the liquid level L2 by the level gauge 81 while the liquefied carbon dioxide is being dispensed from the tank 21. Note that the dispense of liquefied carbon dioxide from the tank 21 continues until the liquid level L2 reaches a predetermined threshold, at which point the dispense is stopped (dispensing is completed).

[0036] Furthermore, the discharged mass acquisition unit 72 calculates the specific gravity of the liquefied carbon dioxide in the tank 21 based on the temperature of the liquefied carbon dioxide in the tank 21 detected by the tank thermometer 82 and the pressure in the tank 21 detected by the tank pressure gauge 83 before the liquefied carbon dioxide is discharged from the tank 21 and after the discharge of the liquefied carbon dioxide from the tank 21 is completed, respectively. Furthermore, the discharged mass acquisition unit 72 calculates the mass of the liquefied carbon dioxide before the liquefied carbon dioxide is discharged from the tank 21 from the liquid level L1 before the liquefied carbon dioxide is discharged from the tank 21 and the specific gravity of the liquefied carbon dioxide. Furthermore, the discharged mass acquisition unit 72 calculates the mass of the liquefied carbon dioxide after the discharge of the liquefied carbon dioxide from the tank 21 is completed from the liquid level L2 after the discharge of the liquefied carbon dioxide from the tank 21 is completed and the specific gravity of the liquefied carbon dioxide. Then, the discharged mass obtaining unit 72 calculates the difference between the mass of the liquefied carbon dioxide before the liquefied carbon dioxide is dispensed from the tank 21 and the mass of the liquefied carbon dioxide after the dispensing of the liquefied carbon dioxide from the tank 21 is completed. In this way, the discharged mass obtaining unit 72 obtains the amount of change in the mass of the liquefied carbon dioxide stored in the tank 21 before the liquefied carbon dioxide is dispensed from the tank 21 and after the dispensing is completed. Note that the discharged mass obtaining unit 72 may, for example, detect the temperature of the liquefied carbon dioxide in the tank 21 detected by the tank thermometer 82 and the pressure in the tank 21 detected by the tank pressure gauge 83 multiple times while the liquefied carbon dioxide is being dispensed from the tank 21, and use the average values ​​thereof to calculate the specific gravity of the liquefied carbon dioxide in the tank 21.

[0037] The discharged mass obtaining unit 72 determines the mass of liquefied carbon dioxide sent to the tank 21 by the first piping system 103 while the liquefied carbon dioxide is being discharged from the tank 21, based on the detection result of the first flow meter 91. Specifically, the discharged mass obtaining unit 72 obtains the volumetric flow rate of liquefied carbon dioxide sent to the tank 21 by the first piping system 103 while the liquefied carbon dioxide is being discharged from the tank 21, detected by the first flow meter 91. The discharged mass obtaining unit 72 obtains the mass flow rate of liquefied carbon dioxide sent to the tank 21 by the first piping system 103, based on the volumetric flow rate of liquefied carbon dioxide sent into the tank 21 by the first piping system 103, the pressure detected by the first pressure sensor 85, and the temperature of the liquefied carbon dioxide detected by the first temperature sensor 86.

[0038] The dispensed mass acquisition unit 72 further acquires the mass of liquefied carbon dioxide dispensed from the tank 21 (the cumulative value from the start to the completion of dispense) based on the change in the mass of the liquefied carbon dioxide in the tank 21 before dispense and after dispense is completed, and the mass flow rate of the liquefied carbon dioxide sent to the tank 21 by the first piping system 103.

[0039] Furthermore, the discharged mass obtaining unit 72 corrects the mass of the liquefied carbon dioxide dispensed from the tank 21 based on the purity of the liquefied carbon dioxide detected by the purity detector 87. In other words, the mass of impurities contained in the liquefied carbon dioxide dispensed from the tank 21 is subtracted from the obtained mass of the liquefied carbon dioxide dispensed from the tank 21. Furthermore, the discharged mass obtaining unit 72 corrects the mass of the liquefied carbon dioxide sent to the tank 21 by the first piping system 103 while the liquefied carbon dioxide is being dispensed from the tank 21 based on the purity of the liquefied carbon dioxide detected by the purity detector 89. Note that the correction of the mass of the liquefied carbon dioxide based on the purity of the liquefied carbon dioxide detected by the purity detectors 87, 89 may be performed each time the mass of the liquefied carbon dioxide in the tank 21 is calculated.

[0040] Here, the discharged mass obtaining unit 72 of the present embodiment obtains an integrated value of the flow rate of liquefied carbon dioxide dispensed from the tank 21 via the second piping system 104 based on the detection result of the second flow meter 92, and obtains the amount of liquefied carbon dioxide dispensed via the second piping system 104. The discharged mass obtaining unit 72 can also compare the flow rate of liquefied carbon dioxide obtained based on the detection result of the second flow meter 92 with the amount of liquefied carbon dioxide dispensed obtained based on the detection results of the level meter 81, the tank thermometer 82, the tank pressure meter 83, the first flow meter 91, the first pressure sensor, and the first temperature sensor 86, as described above. This makes it possible to detect the occurrence of an abnormality with a simple configuration, for example, when an abnormality occurs in at least one of the level meter 81, the tank thermometer 82, the tank pressure meter 83, the first flow meter 91, the first pressure sensor, and the first temperature sensor 86.

[0041] Furthermore, the discharge mass acquisition unit 72 of this embodiment acquires the mass of carbon dioxide in the gas discharged from the combustion device 8 based on the amount of fuel consumed detected by the fuel meter 88. More specifically, the discharge mass acquisition unit 72 calculates the weight consumption of fuel based on the amount of fuel consumed detected by the fuel meter 88, the temperature of the fuel detected by the fuel thermometer 84, and the bunker properties (specific gravity, viscosity, calorific value, etc. of the fuel) of the fuel loaded in the fuel tank 9. Note that information on the bunker properties of the fuel loaded in the fuel tank 9 is available in advance from the manufacturer, etc.

[0042] The discharged mass acquisition unit 72 calculates the amount (mass) of carbon dioxide emitted by burning fuel during navigation based on the calculated weight consumption of fuel and the carbon dioxide conversion factor specified by the IMO (International Maritime Organization).The discharged mass acquisition unit 72 of this embodiment then calculates the greenhouse gas (GHG: Green House Gas) reduction rate based on the difference between the mass of carbon dioxide emitted by burning fuel during navigation and the mass of the liquefied carbon dioxide discharged from the tank 21.

[0043] The information output unit 73 outputs to the outside information based on the calculation results acquired by the discharged mass acquisition unit 72 as described above. Examples of information output to the outside from the information output unit 73 include the mass of liquefied carbon dioxide discharged from the tank 21 and the greenhouse gas (GHG) reduction rate. Examples of output by the information output unit 73 include displaying an image on a monitor device, transmitting data to an external computer terminal, printing a document on a printer, etc.

[0044] (Procedure of Carbon Dioxide Metering Method) Figure 6 is a flowchart showing the procedure of a carbon dioxide metering method according to an embodiment of the present disclosure. As shown in Figure 6, a carbon dioxide metering method S10 according to an embodiment of the present disclosure includes step S11 of acquiring the liquid level in the tank 21, step S12 of acquiring the temperature and pressure in the tank 21, step S13 of acquiring the flow rate of liquefied carbon dioxide fed into the tank 21, step S14 of acquiring the mass of liquefied carbon dioxide dispensed from the tank 21, and step S15 of calculating a greenhouse gas reduction rate.

[0045] In step S11 of acquiring the liquid level in the tank 21, the dispensing mass acquisition unit 72 detects the liquid level L1 in the tank 21 on the level meter 81 before starting to dispense the liquefied carbon dioxide from the tank 21. Also, as shown in Figure 5, the dispensing mass acquisition unit 72 detects the liquid level L2 in the tank 21 on the level meter 81 while the liquefied carbon dioxide is being dispensed from the tank 21.

[0046] In step S12 of acquiring the temperature and pressure inside the tank 21, the dispensing mass acquisition unit 72 acquires the temperature of the liquefied carbon dioxide inside the tank 21 detected by the tank thermometer 82 and the pressure inside the tank 21 detected by the tank pressure gauge 83. Each time the dispensing mass acquisition unit 72 acquires the liquid level inside the tank 21 in step S11, it calculates the specific gravity of the liquefied carbon dioxide inside the tank 21 based on the temperature of the liquefied carbon dioxide inside the tank 21 detected by the tank thermometer 82 and the pressure inside the tank 21 detected by the tank pressure gauge 83. The dispensing mass acquisition unit 72 acquires the amount of change in the mass of the liquefied carbon dioxide inside the tank 21 based on the liquid level at each time point before dispensing and after completion of dispensing calculated in step S11 and the specific gravity of the liquefied carbon dioxide at each time point calculated in step S12.

[0047] Here, in this embodiment, in parallel with the above steps S11 and S12, while the liquefied carbon dioxide is being dispensed from the tank 21, the second flow meter 92 detects the flow rate of the liquefied carbon dioxide dispensed from the tank 21 via the second piping system 104.

[0048] In step S13 of acquiring the flow rate of liquefied carbon dioxide being sent to tank 21, the discharge mass acquisition unit 72 acquires the volumetric flow rate of liquefied carbon dioxide sent to tank 21 by first piping system 103, detected by first flow meter 91, while the liquefied carbon dioxide is being dispensed from inside tank 21. Also in step S13, while the liquefied carbon dioxide is being dispensed from inside tank 21, the first pressure sensor 85 detects the pressure of the liquefied carbon dioxide being sent to tank 21 by first piping system 103, and the first temperature sensor 86 detects the temperature of the liquefied carbon dioxide sent to tank 21 by first piping system 103.

[0049] In step S14 of acquiring the mass of liquefied carbon dioxide dispensed from tank 21, the mass (integrated value) of liquefied carbon dioxide dispensed from tank 21 is acquired based on the amount of change in the mass of liquefied carbon dioxide in tank 21 before and after completion of dispensing, acquired in steps S11 and S12, and the mass flow rate of liquefied carbon dioxide fed to tank 21 by first piping system 103, acquired in step S13. In step S14 of this embodiment, further, the dispensed mass acquisition unit 72 corrects the mass of liquefied carbon dioxide dispensed from tank 21, based on the purity of liquefied carbon dioxide detected by purity detector 87. The dispensed mass acquisition unit 72 corrects the mass of liquefied carbon dioxide fed to tank 21 by first piping system 103 during the dispense of liquefied carbon dioxide from inside tank 21, based on the purity of liquefied carbon dioxide detected by purity detector 89. In step S14, the amount of liquefied carbon dioxide dispensed through the second piping system 104 may be obtained based on the detection result of the second flow meter 92, and the amount of liquefied carbon dioxide obtained based on the detection result of the second flow meter 92 may be compared with the amount of liquefied carbon dioxide dispensed obtained based on the detection results of the level meter 81, the tank thermometer 82, the tank pressure meter 83, the first flow meter 91, the first pressure sensor, and the first temperature sensor 86. In steps S11 to S14, the liquid level, the temperature, pressure, and purity of the liquefied carbon dioxide in the tank 21 are sequentially obtained from before the liquefied carbon dioxide is dispensed from the tank 21 until the dispense of the liquefied carbon dioxide from the tank 21 is completed. The dispensed mass obtaining unit 72 may accumulate the obtained data on the liquid level, the temperature, pressure, and purity of the liquefied carbon dioxide, and calculate the amount of liquefied carbon dioxide dispensed from the tank 21 after the dispense of the liquefied carbon dioxide from the tank 21 is completed. In this embodiment, while liquefied carbon dioxide is being dispensed from the tank 21, the amount of change in liquefied carbon dioxide is calculated each time the liquid level, temperature, pressure, and purity of the liquefied carbon dioxide are acquired, and these values ​​are accumulated sequentially to calculate the amount of liquefied carbon dioxide dispensed. For this reason, in this embodiment, the above-described steps S11 to S14 are performed in parallel.

[0050] In step S15 for calculating the greenhouse gas reduction rate, the discharged mass acquisition unit 72 first acquires the mass of carbon dioxide in the gaseous carbon dioxide discharged from the combustion device 8 based on the fuel consumption detected by the fuel meter 88. The discharged mass acquisition unit 72 calculates the weight consumption of fuel based on the fuel consumption detected by the fuel meter 88, the fuel temperature detected by the fuel thermometer 84, and the bunker properties of the fuel loaded in the fuel tank 9 (such as the specific gravity, viscosity, and calorific value of the fuel). Based on the calculated weight consumption of fuel, the discharged mass acquisition unit 72 calculates the amount of carbon dioxide emitted by burning the fuel during navigation using a carbon dioxide conversion factor specified by the IMO. The discharged mass acquisition unit 72 calculates the greenhouse gas reduction rate based on the difference between the amount of carbon dioxide emitted by burning the fuel during navigation and the mass of the liquefied carbon dioxide discharged from the tank 21. Then, in step S15, information based on the calculation results acquired by the discharged mass acquisition unit 72 is output to the outside.

[0051] (Operation and Effect) In the carbon dioxide metering system 20 of the above embodiment, the mass of liquefied carbon dioxide stored in the tank 21 can be determined based on the liquid level in the tank 21, the temperature in the tank 21, and the pressure in the tank 21. This makes it possible to obtain the change in mass of the liquefied carbon dioxide stored in the tank 21 between before the liquefied carbon dioxide in the tank 21 is dispensed and after the liquefied carbon dioxide in the tank 21 is dispensed. In addition, the mass flow rate of the liquefied carbon dioxide sent from the liquefaction unit 25 to the tank 21 is determined based on the detection result of the first flow meter 91. The mass of the liquefied carbon dioxide dispensed from the tank 21 can be obtained with higher accuracy based on the mass of the liquefied carbon dioxide stored in the tank 21 determined in this manner and the mass flow rate of the liquefied carbon dioxide sent to the tank 21 by the first piping system 103 while the liquefied carbon dioxide is being dispensed from the tank 21. As a result, the mass of the unloaded liquefied carbon dioxide can be obtained with higher accuracy.

[0052] In addition, in the above embodiment, while using a first flow meter 91 that detects the volumetric flow rate of liquefied carbon dioxide, the mass flow rate of liquefied carbon dioxide being sent to the tank 21 via the first piping system 103 can be obtained based on the volumetric flow rate of liquefied carbon dioxide detected by the first flow meter 91, the pressure detected by the first pressure sensor 85, and the temperature of the liquefied carbon dioxide detected by the first temperature sensor.

[0053] Furthermore, in the above embodiment, the second flow meter 92 detects the flow rate of liquefied carbon dioxide discharged outside the tank 21 by the second piping system 104, and the flow rate of liquefied carbon dioxide discharged outside the tank 21 detected by the second flow meter 92 can be compared with the mass of liquefied carbon dioxide discharged from the tank 21 determined using the level meter 81, the tank pressure meter 83, the tank thermometer 82, and the first flow meter 91, thereby enabling simple abnormality detection.

[0054] In addition, in the above embodiment, when the ship is stopped and liquefied carbon dioxide is being discharged from the tank 21, the flow rate of liquefied carbon dioxide in the first piping system 103 is sufficiently smaller than the flow rate of liquefied carbon dioxide in the second piping system 104, so the flow rate of liquefied carbon dioxide detected by the first flow meter 91 can be detected with less error than the flow rate of liquefied carbon dioxide detected by the second flow meter 92.

[0055] In addition, in the above embodiment, the mass of liquefied carbon dioxide dispensed from tank 21 can be obtained with higher accuracy by correcting the mass of liquefied carbon dioxide dispensed from tank 21 based on the purity of the liquefied carbon dioxide.

[0056] In addition, in the above embodiment, the greenhouse gas reduction rate can be calculated based on the mass of carbon dioxide gas emitted from the combustion device 8, which is obtained based on the fuel consumption detected by the fuel meter 88, and the mass of liquefied carbon dioxide dispensed from the tank 21.

[0057] Furthermore, the ship 1 of the above embodiment can provide a ship 1 equipped with a carbon dioxide metering system that can obtain the mass of unloaded liquefied carbon dioxide with higher accuracy.

[0058] In the carbon dioxide metering method S10 of the above embodiment, the mass of liquefied carbon dioxide dispensed from the tank 21 can be obtained based on the temperature and pressure within the tank 21, the amount of change in the liquid level within the tank 21, and the flow rate of liquefied carbon dioxide sent from the liquefaction unit 25 to the tank 21. This makes it possible to obtain the change in mass of liquefied carbon dioxide stored in the tank 21 between before the liquefied carbon dioxide within the tank 21 is dispensed and after the liquefied carbon dioxide within the tank 21 is dispensed. Furthermore, by obtaining the mass of liquefied carbon dioxide sent from the liquefaction unit 25 to the tank 21, the mass of liquefied carbon dioxide dispensed from the tank 21 can be obtained with higher accuracy. As a result, the mass of the unloaded liquefied carbon dioxide can be obtained with higher accuracy.

[0059] Other Embodiments Although the embodiments of the present disclosure have been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design modifications and the like are also included within the scope of the present disclosure. In the above embodiment, the mass flow rate of liquefied carbon dioxide sent to the tank 21 through the first piping system 103 is obtained based on the volumetric flow rate of liquefied carbon dioxide detected by the first flow meter 91, the pressure detected by the first pressure sensor 85, and the temperature of the liquefied carbon dioxide detected by the first temperature sensor. However, this is not limited to this. For example, while using the first flow meter 91 that detects the volumetric flow rate of liquefied carbon dioxide, the mass of liquefied carbon dioxide sent from the liquefaction unit 25 to the tank 21 may be obtained based on the volumetric flow rate of liquefied carbon dioxide detected by the first flow meter 91, the pressure of liquefied carbon dioxide in the tank 21 detected by the tank pressure meter 83, and the temperature of liquefied carbon dioxide in the tank 21 detected by the tank thermometer 82. Furthermore, while using a first flow meter 91 that detects the volumetric flow rate of liquefied carbon dioxide, the mass of liquefied carbon dioxide sent from the liquefaction unit 25 to the tank 21 can be obtained based on the volumetric flow rate of liquefied carbon dioxide detected by the first flow meter 91 and the pressure and temperature of the liquefied carbon dioxide detected by a pressure gauge and a thermometer (neither of which are shown) provided in the liquefaction unit 25.

[0060] Furthermore, the first flow meter 91 may be configured to detect the mass flow rate of the liquefied carbon dioxide sent from the liquefaction unit 25 to the tank 21. This eliminates the need to convert the volumetric flow rate of the liquefied carbon dioxide flowing through the first piping system 103 into a mass flow rate, and makes it easier to calculate the mass of the liquefied carbon dioxide dispensed from the tank 21.

[0061] Furthermore, in the above embodiment, the second flow meter 92 detects the flow rate of liquefied carbon dioxide discharged outside the tank 21 by the second piping system 104, but it may also be configured to detect the pressure and temperature of the liquefied carbon dioxide flowing through the second piping system 104. In this way, based on the volumetric flow rate of liquefied carbon dioxide detected by the second flow meter 92 and the pressure and temperature of the liquefied carbon dioxide flowing through the second piping system 104, it is possible to obtain the mass flow rate of liquefied carbon dioxide discharged from the tank 21 by the second piping system 104.

[0062] In addition, while using a second flow meter 92 that detects the volumetric flow rate of liquefied carbon dioxide, the mass flow rate of liquefied carbon dioxide flowing through the second piping system 104 may be obtained based on the pressure of the liquefied carbon dioxide in the tank 21 detected by the tank pressure meter 83 and the temperature of the liquefied carbon dioxide in the tank 21 detected by the tank thermometer 82.

[0063] The second flow meter 92 may also be configured to detect the mass flow rate of the liquefied carbon dioxide flowing through the second piping system 104. This allows for more accurate abnormality detection by comparing the detection result of the second flow meter 92 with the acquired mass of liquefied carbon dioxide dispensed from the tank 21.

[0064] In addition, in the above embodiment, the purity of the liquefied carbon dioxide is detected using purity detectors 87 and 89, but the detection location for the purity of the liquefied carbon dioxide is not limited to within the first piping system 103 or the second piping system 104, and may be, for example, within the tank 21, etc.

[0065] Furthermore, in the above embodiment, the amount of liquefied carbon dioxide dispensed is obtained from the difference in mass of liquefied carbon dioxide before dispense of liquefied carbon dioxide from tank 21 and after dispense of liquefied carbon dioxide from tank 21 is completed, but this is not limited to this. From before dispense of liquefied carbon dioxide from tank 21 until dispense of liquefied carbon dioxide is completed, the liquid level in tank 21 and the temperature and pressure of the liquefied carbon dioxide in tank 21 may be detected, for example, at predetermined time intervals, and the amount of change in the mass of liquefied carbon dioxide may be sequentially integrated. Similarly, for liquefied carbon dioxide sent from liquefaction unit 25 to tank 21, the volumetric flow rate, pressure, and temperature of liquefied carbon dioxide may be acquired, for example, at predetermined time intervals, from before dispense of liquefied carbon dioxide from tank 21 until dispense of liquefied carbon dioxide is completed, and the mass flow rate of liquefied carbon dioxide sent to tank 21 may be sequentially accumulated.

[0066] <Supplementary Note> The carbon dioxide metering system 20, the ship 1, and the carbon dioxide metering method S10 described in the embodiment can be understood, for example, as follows.

[0067] (1) A carbon dioxide metering system 20 according to a first aspect includes a carbon dioxide recovery unit 23 that recovers gaseous carbon dioxide from a carbon dioxide-containing gas, a liquefaction unit 25 that liquefies the gaseous carbon dioxide recovered by the carbon dioxide recovery unit 23, a tank 21 capable of storing liquefied carbon dioxide, a first piping system 103 that sends the liquefied carbon dioxide liquefied by the liquefaction unit 25 into the tank 21, a level gauge 81 that detects the liquid level in the tank 21, a tank thermometer 82 that detects the temperature in the tank 21, a tank pressure gauge 83 that detects the pressure in the tank 21, a first flow meter 91 that detects the flow rate of the liquefied carbon dioxide sent to the tank 21 by the first piping system 103, and a tank pressure gauge 83 that detects the pressure in the tank 21. and a discharged mass acquisition unit 72 that acquires the mass of liquefied carbon dioxide discharged from tank 21, and the discharged mass acquisition unit 72 determines the mass of liquefied carbon dioxide stored in tank 21 based on the detection results of the level meter 81, the tank thermometer 82, and the tank pressure meter 83, and determines the mass of liquefied carbon dioxide sent to tank 21 by the first piping system 103 based on the detection result of the first flow meter 91, and acquires the mass of liquefied carbon dioxide discharged from tank 21 based on the determined mass of liquefied carbon dioxide stored in tank 21 and the mass of liquefied carbon dioxide sent to tank 21 by the first piping system 103.

[0068] This makes it possible to obtain with higher accuracy the mass of liquefied carbon dioxide dispensed from tank 21 based on the mass of liquefied carbon dioxide stored in tank 21 and the mass of liquefied carbon dioxide sent to tank 21 by first piping system 103. As a result, it is possible to obtain with higher accuracy the mass of unloaded liquefied carbon dioxide.

[0069] (2) The carbon dioxide metering system 20 relating to the second aspect is the carbon dioxide metering system 20 of (1), further comprising a first pressure sensor 85 that detects the pressure of the liquefied carbon dioxide sent from the liquefaction unit 25 to the tank 21, and a first temperature sensor that detects the temperature of the liquefied carbon dioxide sent from the liquefaction unit 25 to the tank 21, and the first flow meter 91 detects the volumetric flow rate of the liquefied carbon dioxide sent to the tank 21 by the first piping system 103, and the discharge mass acquisition unit 72 acquires the mass of the liquefied carbon dioxide sent to the tank 21 by the first piping system 103 based on the volumetric flow rate of the liquefied carbon dioxide detected by the first flow meter 91, the pressure detected by the first pressure sensor 85, and the temperature of the liquefied carbon dioxide detected by the first temperature sensor.

[0070] This allows the mass of liquefied carbon dioxide being sent to tank 21 via first piping system 103 to be obtained based on the volumetric flow rate of liquefied carbon dioxide detected by first flow meter 91, the pressure detected by first pressure sensor 85, and the temperature of liquefied carbon dioxide detected by first temperature sensor, using the first flow meter 91 to detect the volumetric flow rate of liquefied carbon dioxide.

[0071] (3) A carbon dioxide metering system 20 relating to a third aspect is the carbon dioxide metering system 20 of (1), wherein the first flow meter 91 detects the volumetric flow rate of liquefied carbon dioxide sent to the tank 21 by the first piping system 103, and the discharge mass acquisition unit 72 acquires the mass of liquefied carbon dioxide sent from the liquefaction unit 25 to the tank 21 based on the volumetric flow rate of liquefied carbon dioxide detected by the first flow meter 91, the pressure of liquefied carbon dioxide in the tank 21 detected by the tank pressure meter 83, and the temperature of liquefied carbon dioxide in the tank 21 detected by the tank thermometer 82.

[0072] This allows the mass of liquefied carbon dioxide being sent from the liquefaction section 25 to the tank 21 to be obtained based on the volumetric flow rate of liquefied carbon dioxide detected by the first flow meter 91, the pressure of the liquefied carbon dioxide in the tank 21 detected by the tank pressure meter 83, and the temperature of the liquefied carbon dioxide in the tank 21 detected by the tank thermometer 82, using the first flow meter 91 to detect the volumetric flow rate of the liquefied carbon dioxide.

[0073] (4) The carbon dioxide metering system 20 according to the fourth aspect is the carbon dioxide metering system 20 of (1), in which the first flow meter 91 detects the mass flow rate of liquefied carbon dioxide sent from the liquefaction section 25 to the tank 21.

[0074] As a result, by using the first flow meter 91 to detect the mass flow rate of liquefied carbon dioxide being sent from the liquefaction section 25 to the tank 21, the mass of liquefied carbon dioxide dispensed from the tank 21 can be detected more directly.

[0075] (5) The carbon dioxide metering system 20 relating to the fifth aspect is any one of the carbon dioxide metering systems 20 of (1) to (4), and further includes a second piping system 104 that dispenses the liquefied carbon dioxide in the tank 21 to the outside of the tank 21, and a second flow meter 92 that detects the volumetric flow rate of the liquefied carbon dioxide dispensed to the outside of the tank 21 by the second piping system 104.

[0076] As a result, by using the second flow meter 92 to detect the flow rate of liquefied carbon dioxide being discharged outside the tank 21 via the second piping system 104, the flow rate of liquefied carbon dioxide being discharged outside the tank 21 detected by the second flow meter 92 can be compared with the mass of liquefied carbon dioxide being discharged from the tank 21 determined using the level meter 81, tank pressure meter 83, tank thermometer 82, and first flow meter 91.

[0077] (6) The carbon dioxide metering system 20 according to the sixth aspect is the carbon dioxide metering system 20 of (5), in which, when the ship is stopped and liquefied carbon dioxide is being discharged from the tank, the flow rate of the first piping system 103 is smaller than the flow rate of the second piping system 104.

[0078] As a result, the flow rate of liquefied carbon dioxide detected by the first flow meter 91 can be detected with less error than the flow rate of liquefied carbon dioxide detected by the second flow meter 92 .

[0079] (7) The carbon dioxide metering system 20 relating to the seventh aspect is any one of the carbon dioxide metering systems 20 of (1) to (6), and further includes purity detectors 87, 89 that detect the purity of the liquefied carbon dioxide dispensed from the tank 21, and the dispensed mass acquisition unit 72 corrects the mass of the liquefied carbon dioxide dispensed from the tank 21 based on the purity of the liquefied carbon dioxide detected by the purity detectors 87, 89.

[0080] This allows the mass of liquefied carbon dioxide dispensed from tank 21 to be corrected based on the purity of the liquefied carbon dioxide, thereby making it possible to obtain the mass of liquefied carbon dioxide dispensed from tank 21 with higher accuracy.

[0081] (8) The carbon dioxide metering system 20 relating to the eighth aspect is any one of the carbon dioxide metering systems 20 of (1) to (7), further comprising a combustion device 8 that burns fuel and a fuel meter 88 that can detect the amount of fuel consumed by the combustion device 8, and the discharged mass acquisition unit 72 acquires the mass of carbon dioxide in the gas discharged from the combustion device 8 based on the amount of fuel consumed detected by the fuel meter 88, and calculates the greenhouse gas reduction rate based on the acquired mass of carbon dioxide in the gas and the mass of liquefied carbon dioxide discharged from the tank 21.

[0082] This allows the greenhouse gas reduction rate to be calculated based on the mass of carbon dioxide gas emitted from the combustion device 8, which is obtained based on the fuel consumption detected by the fuel meter 88, and the mass of liquefied carbon dioxide dispensed from the tank 21.

[0083] (9) A ship 1 according to a ninth aspect includes a hull 2 ​​and any one of the carbon dioxide metering systems 20 described in (1) to (8).

[0084] This makes it possible to provide a ship 1 equipped with a carbon dioxide inheritance system that can obtain the mass of unloaded liquefied carbon dioxide with greater accuracy.

[0085] (10) The carbon dioxide metering method S10 relating to the tenth aspect is a carbon dioxide metering method S10 in any one of the carbon dioxide metering systems 20 of (1) to (8), and includes the steps of: step S11 of acquiring the liquid level in the tank 21; step S12 of acquiring the temperature and pressure in the tank 21; step S13 of acquiring the flow rate of liquefied carbon dioxide sent from the liquefaction unit 25 to the tank 21; and step S14 of acquiring the mass of liquefied carbon dioxide dispensed from the tank 21 based on the temperature and pressure in the tank 21, the change in the liquid level in the tank 21, and the flow rate of liquefied carbon dioxide sent from the liquefaction unit 25 to the tank 21.

[0086] This makes it possible to obtain the change in mass of the liquefied carbon dioxide stored in tank 21 between before the liquefied carbon dioxide in tank 21 is dispensed and after the liquefied carbon dioxide in tank 21 is dispensed. Furthermore, by obtaining the mass of the liquefied carbon dioxide sent from liquefaction unit 25 to tank 21, it is possible to obtain with higher accuracy the mass of the liquefied carbon dioxide dispensed from tank 21. As a result, it is possible to obtain with higher accuracy the mass of the unloaded liquefied carbon dioxide.

[0087] According to the carbon dioxide metering system, ship, and carbon dioxide metering method disclosed herein, the mass of unloaded liquefied carbon dioxide can be obtained with greater accuracy.

[0088] DESCRIPTION OF SYMBOLS 1 Ship 2 Hull 2a Bow 2b Stern 3A, 3B Side 4 Ship bottom 5 Upper deck 6 Superstructure 7 Cargo carrying compartment 8 Combustion device 9 Fuel tank 11 Cargo tank 20 Carbon dioxide metering system 21 Tank 23 Carbon dioxide capture unit 25 Liquefaction unit 50 Arithmetic unit 51 CPU 52 ROM 53 RAM 54 Storage 55 Signal transmission / reception module 70 Signal input unit 71 Information acquisition unit 72 Discharge mass acquisition unit 73 Information output unit 81 Level gauge 82 Tank thermometer 83 Tank pressure gauge 84 Fuel thermometer 85 First pressure sensor 86 First temperature sensor 87 Purity detector 88 Fuel gauge 89 Purity detector 91 First flow meter 92 Second flow meter 101 Fuel supply piping system 102 Exhaust gas pipe 103 First piping system 104 Second piping system 105 Discharge piping system 108 Lifting pump L1 Liquid level L2 Liquid level

Claims

1. A system comprising: a carbon dioxide capture unit that captures gaseous carbon dioxide from a carbon dioxide-containing gas; a liquefaction unit that liquefies the gaseous carbon dioxide captured by the carbon dioxide capture unit; a tank capable of storing liquefied carbon dioxide; a first piping system that sends the liquefied carbon dioxide liquefied by the liquefaction unit into the tank; a level gauge that detects a liquid level in the tank; a tank thermometer that detects a temperature in the tank; a tank pressure gauge that detects a pressure in the tank; a first flowmeter that detects a flow rate of the liquefied carbon dioxide sent to the tank by the first piping system; and a discharged mass acquisition unit that acquires a mass of the liquefied carbon dioxide discharged from the tank, wherein the discharged mass acquisition unit: A carbon dioxide metering system that calculates the mass of liquefied carbon dioxide stored in the tank based on the detection results of the level gauge, the tank thermometer, and the tank pressure gauge, and calculates the mass of liquefied carbon dioxide sent to the tank by the first piping system based on the detection results of the first flow meter, and obtains the mass of liquefied carbon dioxide dispensed from the tank based on the calculated mass of liquefied carbon dioxide stored in the tank and the mass of liquefied carbon dioxide sent to the tank by the first piping system.

2. A carbon dioxide metering system as described in claim 1, further comprising a first pressure sensor that detects the pressure of liquefied carbon dioxide sent from the liquefaction unit to the tank, and a first temperature sensor that detects the temperature of the liquefied carbon dioxide sent from the liquefaction unit to the tank, wherein the first flow meter detects the volumetric flow rate of liquefied carbon dioxide sent to the tank by the first piping system, and the discharged mass acquisition unit acquires the mass of liquefied carbon dioxide sent to the tank by the first piping system based on the volumetric flow rate of liquefied carbon dioxide detected by the first flow meter, the pressure detected by the first pressure sensor, and the temperature of the liquefied carbon dioxide detected by the first temperature sensor.

3. The carbon dioxide metering system of claim 1, wherein the first flow meter detects the volumetric flow rate of liquefied carbon dioxide being pumped into the tank through the first piping system, and the discharge mass acquisition unit acquires the mass of liquefied carbon dioxide being pumped from the liquefaction unit to the tank based on the volumetric flow rate of liquefied carbon dioxide detected by the first flow meter, the pressure of the liquefied carbon dioxide in the tank detected by the tank pressure gauge, and the temperature of the liquefied carbon dioxide in the tank detected by the tank thermometer.

4. The carbon dioxide metering system according to claim 1, wherein the first flow meter detects the mass flow rate of liquefied carbon dioxide sent from the liquefaction section to the tank.

5. A carbon dioxide metering system as described in any one of claims 1 to 4, further comprising: a second piping system for discharging liquefied carbon dioxide in the tank to the outside of the tank; and a second flow meter for detecting the volumetric flow rate of the liquefied carbon dioxide discharged to the outside of the tank by the second piping system.

6. The carbon dioxide metering system according to claim 5, wherein when the ship is stopped and liquefied carbon dioxide is being discharged from the tank, the flow rate in the first piping system is smaller than the flow rate in the second piping system.

7. A carbon dioxide metering system as described in any one of claims 1 to 4, further comprising a purity detector that detects the purity of the liquefied carbon dioxide dispensed from the tank, wherein the dispensed mass acquisition unit corrects the mass of the liquefied carbon dioxide dispensed from the tank based on the purity of the liquefied carbon dioxide detected by the purity detector.

8. A carbon dioxide metering system as described in any one of claims 1 to 4, further comprising: a combustion device that burns fuel; and a fuel meter capable of detecting the amount of fuel consumed by the combustion device, wherein the discharged mass acquisition unit acquires a mass of carbon dioxide gas discharged from the combustion device based on the amount of fuel consumed detected by the fuel meter, and calculates a greenhouse gas reduction rate based on the acquired mass of carbon dioxide gas and the mass of liquefied carbon dioxide discharged from the tank.

9. A ship comprising a hull and a carbon dioxide metering system according to any one of claims 1 to 4.

10. A carbon dioxide metering method in a carbon dioxide metering system described in any one of claims 1 to 4, comprising the steps of: acquiring a liquid level in the tank; acquiring a temperature and pressure in the tank; acquiring a flow rate of liquefied carbon dioxide pumped from the liquefaction unit to the tank; and acquiring a mass of liquefied carbon dioxide dispensed from the tank based on the temperature and pressure in the tank, the amount of change in the liquid level in the tank, and the flow rate of liquefied carbon dioxide pumped from the liquefaction unit to the tank.

Images